Iran’s Fordow uranium enrichment plant was nearly completed as of the last IAEA report (16 Nov 2012). See my previous commentary on that report here. The Fordow plant, at 1/4th capacity produces 5 kg of 20% U-235 per month. Another fourth of the plant was ready to begin enrichment as of the most recent IAEA inspection that preceded the 16 Nov 2012 report. The rest of the plant needed additional work to begin enrichment, but all of the centrifuges were installed.

In all likelihood, Fordow has been running at half capacity since mid-November, and at full capacity not long thereafter (maybe since early December). At half capacity, the plant produces 10 kg of 20% U-235 per month; at full capacity, 20 kg per month. The IAEA reports that Iran had 134.9 kg of 20% U-235 in storage as of mid-November 2012. If the Fordow plant ran at half capacity (10 kg/month) for the last half of November, it produced an additional 5 kg of 20% U-235, making the total as of December first: 139.9 kg.

Assuming the Fordow plant operates at full capacity for all of December and subsequent months, Fordow adds 20 kg of 20% U-235 gas to the stockpile each month. The Natanz plant is mostly focused on bringing uranium up to the 3.5% U-235 enrichment level. But two sets of tandem centrifuges, the same capacity as 1/4th the Fordow plant, are dedicated to enriching uranium to 20%, producing about another 5 kg of 20% gas per month. So for the last half of November, Natanz produced another 2.5 kg, bringing the total as of 1 December to about:142.4 kg of 20% U-235 gas.

Total 20% U-235 produced each month by Fordow (20 kg/mo.) and Natanz (5 kg/mo.) combined is approximately 25 kg. Thus, Iran’s 20% U-235 gas stockpile increases by approximately 12.5 kg every one half month (which is about 0.8 kg/day).

The 240 kg/1.0 month breakout point is particularly significant, because it represents the point at which Iran can breakout without having to first reconfigure the centrifuges at Natanz to a tandem configuration from the current single cascade configuration. This reduces breakout time by about 0.5 months, the time needed for reconfiguring the Natanz centrifuges. Fordow cascades are already tandem.

Barring a military strike by Israel and the U.S., it seems clear that Iran will have enough 20% U-235 gas for a breakout (if they do not already have enough) by sometime in mid-January of 2013. With Israeli elections scheduled for 22 January 2013, an Israeli strike before then, or even immediately afterward, is highly unlikely. And the reelection of President Obama has decreased the likelihood of an early U.S. strike. Obama has not favored military action, but prefers sanctions and diplomacy.

The earliest likely date for a military strike by the U.S. and Israel seems to be March of 2013, not long after the next IAEA report on Iran is released in Feb. 2013. But Iran will reach breakout capability in January. Then if no military strike occurs in March, Iran will reach the one month breakout point by the end of March.

And that is the Rosy Scenario. There are several possibilities that worsen the situation. In a number of tenable scenarios, the above breakout points are reached much sooner.

If Iran has 25 kg of U-235 gas from its Fuel Plate Fabrication Plant to divert from making uranium oxide back to Natanz or Fordow, then it reaches each breakout point one month sooner. If Iran has been cheating IAEA inspections, so that it has produced more 20% U-235 than we know, each breakout point is reached sooner. If Iran deceived the IAEA, so that they did not really convert 96.3 kg of U-235 gas to uranium oxide metal at its Fuel Plate Fabrication Plant, then they already have enough U-235 gas for a one month or less breakout.

On that point, there have been a number of news stories and commentary saying that Iran signaled its willingness to slow down its nuclear program by converting 96.3 kg of 20% U-235 gas into the oxide metal (which is impractical for further enrichment). But that interpretation of Iran’s action is contrary to their actions in all other respects:

They continue to increase the number of centrifuges at Natanz, toward an apparent goal of 25,000 or perhaps 50,000 total centrifuges (25k in each of two Halls). They have completed installment of all the centrifuges at Fordow. They have refused to permit inspections of Parchin, while they thoroughly clean the site, covering their activities there. They are working on the design of more advanced centrifuges. They refuse to agree to any limits on nuclear enrichment, even in response to increasingly harsh sanctions. Nothing Iran has done shows any willingness to slow the enrichment process.

Therefore, I suggest that the 96.3 kg of gas that was apparently used to make uranium oxide plates was diverted to a third secret enrichment facility (or at least stored somewhere in anticipation of a breakout). Iran could have obtained uranium oxide from an outside source, such as China, to show to inspectors. Such a deception is not beyond the ability and willingness of the Iranian regime.

Finally, if Iran has a third secret enrichment plant, possibly with the more advanced IR-2m centrifuges — anything goes. They may already be producing 90% U-235 (WGU) covertly, and they may already have enough U-235 metal for one bomb.

So the best case scenario is that Iran reaches the 1.7 month breakout point in mid-January, 2013, and the one month breakout point at the very end of March, 2013. All other scenarios are much worse.